Modern computer operating systems include one or more file system components. Such components are responsible for storing, organizing, updating, and retrieving data for normal application programs in a manner that is largely transparent to the user of the computer applications running on a computer system employing such an operating system. The specific features supported by these file systems can vary dramatically, both in terms of their model of organization, the manner in which they communicate with their underlying storage, and the specific features they make available to application programs, and thus, ultimately, to the users of those application programs.
Some file systems support specialized data transformation features, such as encryption, compression, storage of multiple disjoint data attributes (such as streams, resource forks, property lists, extended attributes, etc.), transactional support, localized language support, etc. However, these features are characteristics of the specific file system, and different machines in a computer system may use different file systems. Accordingly, applications running on the computer system are unable to take advantage of these specialized features unless all components of the computer system use the same file system. Applications may individually support such features by incorporating their own unique features but this technique does not make the features available to existing applications, limiting overall usefulness.